The reason I'm asking this question is when I'm fully rested and my senses are "normal" (whatever the hell that is) I'm to afraid to speak what's on my mind because I feel that I will say something to offend someone or make myelf look like a fool.

Drunk, sleep deprived, and extremely anxious about something *else* (other than speaking) will all reduce inhibitions. You are clearly inhibited about speaking.
Aim at a happy medium -- *some* inhibitions are a good thing -- you don't want to be blurting out your entire personal history to strangers, or saying every criticism that comes to mind.
You can get counselling to help you relax and express yourself more easily.